A cyclic generator for values in an iterable

cycle.ts

// implementation ported from
// https://docs.python.org/3/library/itertools.html#itertools.cycle
function* cycle<T>(iterable: Iterable<T>) {
    const saved: T[] = []
    for (let element of iterable) {
        yield element
        saved.push(element)
    }
    while (saved.length > 0) {
        for (let element of saved) {
            yield element
        }
    }
}